This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The Anatomic Pathology Core consists of the Necropsy, Histology, and Tissue Collection and Distribution Units and is responsible for post-mortem examinations, tissue collection and distribution, fixation, processing, slide preparation, routine and special staining. It is a center policy that a cause of death is determined, if possible, for all animals that die at the center, whether of natural or experimental causes. This allows us to monitor and document all infectious agents and disease processes that occur within the colony and provides an opportunity to discover new diseases, which may be useful models. In addition, most major research areas at the center depend heavily on anatomic pathology support as an integral part of the research. In 2008, a total of 781 necropsies and 378 biopsies were performed by the Core. The Anatomic Pathology Core Laboratory instrumentation includes 3 Microm HM325 microtomes and one automated Leica RM2145 microtome for preparing thin and thick tissue sections for routine H&E and special staining;sections for confocal microscopy, labeling studies with antibodies and molecular probes (performed in the Molecular Pathology Core). We also utilize a Leica ASP 300 tissue processor, a Tissue-Tek embedding station, and assorted water baths, ovens, microscopes and a computer work station. This year the Core produced 21,383 research slides and an additional 3,648 un-sectioned blocks . These totals, when classified by source, are 13,757 slides and 2,539 additional blocks for core scientists and 7,646 slides and 1,109 additional blocks for affiliated scientists. We intend to automate the slide staining and cover-slipping processes in the near future to improve the consistency of the produced slides and to further reduce the chemical exposure to our staff. Currently we employ three full time histologists with a combined 40 years'laboratory experience. The AIDS research program is a major user of core services.